Ignition system for a fuel cell hydrogen generator

ABSTRACT

An ignition system for initiating a fuel cell hydrogen production cycle on demand comprising a module having heat exchanger functions interconnected in an adjacent heater/vaporizer relationship in which a first heat exchanger section in the module is connected to a source of hydrogen enriched gas to provide an initial energy burst to begin the vaporization of liquid hydrocarbons for use in the hydrogen producing cycle; and in which, after system start up, the module section may be inactivated or integrated in the hydrogen producing cycle.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation-in-part of our co-pendingapplication “Micro Component Liquid Hydrocarbon Reformer System andCycle for Producing Hydrogen,” Ser. No. 09/803,592, filed on Mar. 9,2001.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to an ignition system for ahydrogen generation process that is used to provide a source of hydrogenfor a fuel cell. A micro component start module is provided. In general,the invention initiates a hydrogen generation fuel cell system with aninstantaneous burst of energy derived from the combustion of a minorquantity of stored hydrogen. Once initiated, the integrated systemproduces hydrogen gas for powering a fuel cell for automotive and otherscalable power requirements where a discrete or mobile source ofhydrogen in a predetermined on demand quantity is desired.

[0003] Hydrogen fuel cells are non-polluting, highly efficient powersources. See, e.g., FUEL CELLS GREEN POWER, Los Alamos NationalLaboratory, U.S. Department of Energy, 1999.<www.eren.doe.gov/RE/hydrogen_fuel_cells.html>. Despite their desirablecharacteristics, the use of fuel cells in motor vehicle andtransportation applications is hindered because convenient, safe andmobile sources of hydrogen having a size and operation characteristicsappropriate for a vehicle (e.g., quick start up and shut down) or othermobile or predetermined output requirements are not available.

[0004] It is an object of the invention to provide an on demand ignitionsystem for a cycle that produces hydrogen gas to feed an electric powerproducing fuel cell. It is a further object to provide an ignitionsystem that is reliable, convenient, safe, and adaptable for fuel cellsystems used in automotive, mobile, and other discrete low powerrequirement uses in which on demand start up is a requirement.

[0005] The prior art considers steam reformer hydrogen processor systemsto be difficult to use with motor vehicles because, inter alia, thesteam reforming process requires an extended time in a start mode beforea continuous cycle can be initiated. See, “Fuel Cell TechnologyAutomotive Engineer, September 2000, pages 78 et seq. Delays anddifficulties in starting an automobile or other mobile power sourcenegatively impact the acceptability of the technology because on demanduse is a pre-condition for such applications. Hydrogen storagerequirements have similarly hindered vehicular, mobile and otherconsumer uses of fuel cells.

[0006] It is an object of the invention to provide a start module forinitiating a gas production cycle in a hydrogen generation system usedwith a fuel cell stack. In a preferred embodiment, it is an object toprovide a device that enables a reliable and efficient quick start for asteam reforming process for powering hydrogen fuel cells in automotive,mobile and other on demand applications. In a fuel cell system, theinvention provides an instantaneous burst of energy sufficient toinitiate a hydrogen producing cycle, and reduces the volume and quantityrequirements for hydrogen storage in the system.

BRIEF SUMMARY OF THE INVENTION

[0007] In the invention, a small quantity of hydrogen gas from anexternal source is catalytically combusted to provide a heat source tovaporize liquid hydrocarbons and essentially instantaneously initiatethe hydrogen producing process in a fuel cell system. Once initiated, acontinuously balanced reaction cycle in the system converts a liquidhydrocarbon such as gasoline (a mixture of 50 or more hydrocarbons,modeled by the iso-octane C₈H₁₈ component) and water into a hydrogen(H₂) enriched gas fuel for powering the fuel cell.

[0008] The invention is described more fully in the followingdescription of the preferred embodiment considered in view of thedrawings in which:

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0009]FIG. 1 is a schematic diagram of an embodiment of the ignitionsystem.

[0010]FIG. 1A is a schematic diagram showing the ignition system inrelation to a steam reformer process for producing hydrogen to power afuel cell

[0011]FIG. 1B is a schematic diagram showing the ignition system inrelation to an auto thermal system hydrogen for powering a fuel cell.

[0012]FIG. 2A is a diagram of an ignition system with two microcomponent combustor/vaporizer heat exchanger units, interconnected with(a) starting sources of hydrogen gas and liquid hydrocarbons, and inturn, with (b) the hydrogen producing/fuel cell cycle.

[0013]FIG. 2B is an alternate embodiment of the system of FIG. 2A inwhich a catalytic pre-combustor for hydrogen provides energy to a heatexchanger unit.

[0014]FIG. 3A is a diagram of an example of an ignition system with asingle micro component combustor/vaporizer heat exchanger unitinterconnected with a supply of hydrogen used in a minor quantity forstart up and the hydrocarbon fuel supply.

[0015]FIG. 3B is an alternate embodiment of the system of FIG. 3Aincluding pre-combustors for the hydrogen and hydrocarbons before theheat exchanger unit.

[0016]FIG. 4A shows an embodiment with an integrated module combiningtwo combustor/vaporizer heat exchanger units in a single component.

[0017]FIG. 4B shows an embodiment with an integrated module combiningtwo heater/vaporizer heat exchanger units in a system including metalfoam combustors for hydrogen or hydrocarbons, or both, in respectiveflow paths to the heater/vaporizer/heater module.

[0018]FIG. 4C shows an embodiment with an integratedheater/vaporizer/heater module heat exchanger units in a systemincluding flame combustors for hydrogen or hydrocarbons, or both, inrespective flow paths.

[0019]FIGS. 5A, 5B, 5C, 5D and 5E respectively depict (a) across-section of a wavyplate heat exchanger assembly; (b) a perspectiveview of a wavyplate heat exchanger assembly (sides omitted); (c) adetail of a wavyplate channel section with a catalyst on one side of theseparator; and the channel width to channel depth aspect ratio in (d)wavyplate channels and (e) angled channels in the assemblies.

[0020]FIGS. 6A, 6B and 6C respectively depict cross-sections (FIGS. 6Aand 6B) and an exploded view of dual wavyplate module embodiments withheater-combustor/vaporizer/heater-combustor configurations.

DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENT

[0021] The invention is an ignition system or start module forinitiating reactions in a steam reformer or auto thermal system thatproduces hydrogen to power a fuel cell. An instantaneous burst of energyachieved from the combustion of a minor quantity of stored hydrogeninitiates the hydrogen production cycle. The system utilizes a pair ofmodules, or a single module, having vaporizer and heat exchangerfunctions occurring in one or a plurality of laterally adjacent channelsthat direct laminar fluid flow. Regulator valves interconnected withflow paths for hydrogen and hydrocarbons in the system control theignition process. FIG. 1 shows an embodiment of the system including twomicro component heat exchangers (“HEX” units) 1 and 2, each havingvaporizer 1v and 2v and combustor/heater 1c/h and 2c/h sectionsinterconnected by control valves Va, Vb, Vc and Vd to hydrogen 3 andliquid hydrocarbon 4 storage devices. The ignition system is operativelyinterconnected to the hydrogen generation/fuel cell cycle to provide atthe start, and thereafter, vaporized hydrocarbons 6 for the hydrogengeneration/fuel cell cycle. After start up, the ignition HEX unit 2receives fuel cell off gas 5 from the hydrogen generation/fuel cellcycle to provide combustion heat energy for the hydrocarbon vaporizer.

[0022] At start up, valve Vc opens to introduce a flow of hydrogen intothe ignition module for a limited period until the associated hydrogenproduction/fuel cell cycle starts. The hydrogen is catalyticallycombusted to provide heat introduced to the heater side 1c/h of firstHEX unit 1. Valve Va opens and liquid hydrocarbon is directed to theinlet of vaporizer side 1v of unit 1. Vaporized hydrocarbons exit tovalve 1v; Valve Vd is switched to direct the vaporized hydrocarbons,which are catalytically combusted, to side 2c/h of HEX unit 2.Combustion may occur before, or within sections 1c/h and 2c/h. Thecombustion heat generated vaporizes liquid hydrocarbons introduced tovaporizer side 2v upon the opening of valve Vb. The principal proportionof the hydrocarbons vaporized 6 in 2v are directed to the hydrogengeneration system for the fuel cell; a minor portion of the vaporizedhydrocarbons 7, in the order of approximately 3% to approximately 12% bymass, are circulated to the heater/combustor side 2c/h of unit 2. Oncethe hydrogen generation system is initiated, valves Va and Vc close andHEX module 1 is inactivated. Fuel cell off gas 5 is introduced into thehydrocarbon flow stream directed to heater/combustor 2c/h side of heatexchanger 2 to provide a source of combustion for heat energy introducedin the HEX unit.

[0023] Inlet orifices from a stored source of hydrogen direct a minorquantity of hydrogen to be catalytically combusted to provide initialstarting heat energy. Liquid hydrocarbons are simultaneously introducedinto the vaporizer in the heat exchanger unit and vaporized forprocessing in the hydrogen producing system. Stored hydrogen, such as isa component in fuel cell off gas, is used as the starter initiator toheat the vaporizer. A quantity of stored hydrogen may also be mixed withthe vaporized hydrocarbons in the feed stock directed to the combustorheaters in the hydrogen reforming system.

[0024] The initial combustion of a minor quantity of external hydrogenstarts the hydrogen production cycle. Once started, stoiciometricquantities of reactants in the hydrogen production/fuel cell system aremaintained in balance in a low pressure operating cycle regardless ofpower drawn from the fuel cell as the system runs according to thepredetermined cycle. The ignition system is adapted for use particularlywith the steam reformer fuel cell system described in our co-pendingapplication Ser. No. 09/803,592 filed on Mar. 9, 2001, although theignition system may be adapted to auto thermal systems. The starterincludes an ignition stage combustor energized by hydrogen otherwisestored proximate the steam reforming apparatus. Once operating, the fuelsource for the hydrogen producing cycle comprises fuel cell off gas,hydrocarbons, and water, and the start function of the module is notrequired as an element of the fuel cell system

[0025] An example of a mobile fuel cell system interconnected with theignition system of the invention is shown in FIG. 1A. Steam reformerbased fuel processor system 10 is interconnected with fuel cell stack 11which in turn connects with off gas buffer 12. The steam reformer systemutilizes fuel cell off gas from the cycle to provide combustion and heatenergy for use in combustor and heat exchange devices (e.g., unit 10cand section 14c of HEX unit 14 ) in the system. The hydrogen producingsystem includes water source 15 (which may comprise stored recycledcondensate from fuel cell off gas) and hydrocarbon storage unit 16. Thehydrocarbon tank 16 is operatively interconnected to starter 20 and tothe hydrogen reforming system. Starter 20 in a first embodiment includesa pair of micro component vaporizer/combustor heat exchange units 21 and22 each having separate and adjacent combustor 21c and 22c and vaporizer21v and 22v sections. The starter includes control valves V1, V2, V3 andV4 operatively disposed to regulate the flow of hydrogen andhydrocarbons in the system to control the interconnection of theignition system to the related hydrogen producing cycle.

[0026] The powered fuel cell stack 11 produces off-gas comprising H₂,CO₂, and water vapor (H₂O) that are cycled in the system. The specificH₂ cycle, although part of a discrete mobile fuel cell unit, is not acritical element of the invention. Starter 20 is provided as anintegrated module. In a preferred embodiment, the internalconfigurations of the heat exchanger sections are described inco-pending applications Ser. No. 09/627,267 filed Jul. 28, 2000 and Ser.No. 09/803,592, filed on Mar. 9, 2001 owned by the assignee of thepresent application and incorporated by reference herein as if set forthin full.

[0027] As shown in FIG. 1A, starter 20 comprises a pair of microcomponent heat exchanger units 21 and 22 each having combustor sections21c and 22c adjacent to vaporizer sections 21v and 22v.

[0028] The start module 20 is interconnected with a liquid hydrocarbon(e.g., gasoline) source 16 and a source of H₂ gas 18 which may be anexternal source of H₂ or stored fuel cell off gas having an H₂ componentthat is otherwise generated and recycled in the system cycle. A buffertank for off gas in the fuel cell cycle, if needed, is shown as 12.Valves V1, V2, V3 and V4 control the ignition system and itsinterconnection with the hydrogen reformer/fuel cell system.

[0029] At ignition, valve V1 is opened simultaneously with, or slightlybefore valve V2. Opening valve V1 introduces stored H₂ from storage unit18 into the combustor section 21c of heat exchange unit 21, where heatenergy is instantaneously generated by the catalytic combustion ofhydrogen. Liquid hydrocarbons from tank 16 are introduced into adjacentvaporizer section 21v and are likewise instantaneously vaporized, andthrough open valve V3, pass to combustor section 22c of heat exchangemodule 22 where an additional flow of liquid hydrocarbon permitted byopen valve V1 is introduced to vaporizer section 22v. In section 22v,the hydrocarbons are vaporized and a portion thereof are in turnintroduced to combustor section 22c. Valve V4 allows the feedback of aportion of vaporized hydrocarbons to combustor 22c and the introductionof the vaporized hydrocarbons into the hydrogen generation fuel cellcycle where combustion of the vaporized hydrocarbons generatessufficient heat to initiate the steam reforming reaction. After thecycle starts, valve V1 closes the flow of hydrocarbons to vaporizer 21vand valve V2 closes to terminate the flow of hydrogen to combustor 21c.V3 closes to prevent back flow into vaporizer 21v. V1 continues to allowthe flow of liquid hydrocarbons to vaporizer 22v, where, once the steamreforming or auto thermal cycle begins, hydrogen containing fuel celloff gas, introduced through valve V4 and mixed with a proportion ofvaporized hydrocarbons provides the energy source for the combustors inthe system as the fuel cell cycle operates, FIG. 1B shows aninterconnection of the ignition unit with an auto thermal hydrogenproducing cycle showing an additional vaporizer 14′/combustor 14c′ HEXunit.

[0030] Table I provides an example of the micro component heat exchangersection properties of the two HEX units 21 and 22 in the system.Functions of and catalysts on the separator wavyplate that divides therespective module sections are described: TABLE I MODULE SECTIONPROPERTIES Unit 21: Combustor 21c: Function: Hydrogen is combusted.Catalyst on wavyplate separator: Pd Unit 21: Vaporizer 21v: Function:Hydrocarbons are vaporized. Catalyst on wavyplate separator: None. Unit22: Combustor 22c: Function: Step 1 (start): Vaporized hydrocarbons from21v are mixed with air and combusted; Heat energy is directed tovaporizer 22v. Function: Step 2 (after start): Vaporized hydrocarbonsfrom 22v are mixed with fuel cell off gas and combusted; Heat energy isdirected to vaporizer 22v. Catalyst on wavyplate separator: Pt/Pd Unit22: Vaporizer 22v: Function: Liquid hydrocarbons are vaporized. Catalyston wavyplate separator: None.

[0031]FIG. 2A illustrates the ignition system as a unit including theheat exchange micro components and valves and the systeminterconnections, separate from the hydrogen producing system and fuelcell apparatus with which the ignition system is used. FIG. 2B shows anadaptation of the system in which the heater side of the HEX unit doesnot include a catalyst. Between the hydrogen source and the flow path toside 1h of the HEX unit is a metal foam catalyst 1m ( a metal foamimpregnated with a catalyst material) unit that initiates the combustionof hydrogen. Heat from the catalytic combustion of hydrogen in unit 1mis introduced to section 1h of the micro component HEX device thatfunctions, in this example, solely as a heat exchanger to inducevaporization of the liquid hydrocarbons introduced on the opposite sideof the wavyplate in the exchanger.

[0032]FIG. 3A depicts a single unit micro component utilized as thesystem starter. As in the above embodiments, the micro component heatexchanger assembly includes an enclosure with inlet and outlet portsconnected to laminar flow channel sections on opposite sides of awavyplate separator in the assembly. In the FIG. 3A embodiment, theignition unit includes heat exchanger module 30 with combustor 30c andvaporizer 30v sections on the opposite sides of the HEX unit. Valve V35controls the flow of hydrocarbons into the system. The opposite sides ofthe HEX unit are interconnected with each other and with the fuel cellsystem by valves V31 and V32. Separate feeds of hydrogen andhydrocarbons to the unit at the start are controlled by valves V31 andV35. At the start, V31 and V35 open to allow hydrogen into catalyticcombustor 30c and hydrocarbons into vaporizer 30v on the opposite sidesof the HEX unit 30. Once the fuel cell system is running V31 closes andshuts down the introduction of hydrogen, but opens to allow theintroduction of fuel cell off gas into combustor 30c. The flow ofhydrocarbons through vaporizer 30v continues with a portion of thevaporized hydrocarbons being fed back to the combustor 30c controlled byregulator valve or valves V32. The major portion of the vaporizedhydrocarbons are introduced to the fuel cell system where a portion ofthe vaporized hydrocarbons are processed in a steam or auto thermalreformer and a further portion is mixed with off gas to provide heatenergy for the system. The device of FIG. 3A requires a combustioncatalyst on side 30c useful with both hydrogen and hydrocarbons.

[0033]FIG. 3B shows an alternate embodiment of the HEX configuration ofFIG. 3A, further including metal foam catalyst combustors used withhydrogen and hydrocarbons 31m and 33m in advance of the HEX units. Here,the section 30h of the HEX unit is not catalytically active, butfunctions as one side of a heat exchanger for the vaporizer section 30vof the HEX unit.

[0034]FIG. 4A shows a sandwich assembly of acombustor/vaporizer/combustor micro component starting device. Table IIspecifies module section functions and identifies the catalysts on theside of the separator wavyplate that divides the respective modulesections: TABLE II MODULE SECTION PROPERTIES Combustor 40cH: Function:Hydrogen is mixed with air and burned. Catalyst on wavyplate separator:Pd Vaporizer 40v: Function: Hydrocarbons are vaporized. Catalyst onwavyplate separator: None Combustor 40cHC: Function: Vaporizedhydrocarbons, mixed with fuel cell off gas, are combusted and heatenergy is directed to vaporizer 40v. Catalyst on wavyplate separator:Pt/Pd

[0035]FIG. 4B shows an alternate embodiment of the HEX configuration ofFIG. 4A, further including metal foam catalyst combustors used in theflow streams of one or both of 40 cH (hydrogen) and 40 cHC (hydrocarbon)in advance of flow to the heater sides 40 hH and 40 hHC of theheater/vaporizer/heater module 40. Similarly, FIG. 4C shows anembodiment with flame or spark initiated combustors 40 fH and 40 fHC inthe hydrogen and hydrocarbon flow streams to the vaporizer module. Inthese embodiments, the side(s) of the HEX unit preceded by thecombustor(s) is (are) not catalytically active, but functions as aheater in a heat exchanger for the vaporizer section of the HEX unit.

[0036] The configurations of various micro component heat exchangermodule assemblies are shown in FIGS. 5A and 5B corresponding to the heatexchanger units referenced in FIGS. 1A and 1B and 2A and 2B (21 and 22)and FIGS. 3Aand 3B (30). The units provide separate laminar fluid flowsdirected in the separate sections on opposite sides of a wavyplate in amodule. The module includes an enclosure with a top, bottom and sides(not shown in certain of the drawings for purposes of clarity). Eachcombustor or vaporizer section includes inlet and outlet orifices forthe introduction and exhaust of fluid flow therein. FIG. 5A is a crosssectional view of a module embodiment 50 showing an enclosure having top51, bottom 53, and sides 52 and 54. (front and rear sides not shown) Inthe view of a module of FIG. 5B, top inlet and outlet orifices are shownat 51I and 51O; the inlet and outlet orifices on the bottom side 53 aresimilarly configured. The wavyplate separator 55 divides the module intoheater/combustor 55A and vaporizer 55B sections on the opposite sides ofthe plate where laminar fluid flow occurs in the unit.

[0037] Depending on design parameters, laminar fluid flows through themodule sections with respect to individual module sections may be in thesame direction (co-flow) or in opposite directions (counter flow). Microchannels in the units have a predetermined point to point separation andare optimally designed to have a maximum depth (a high aspect ratio)allowing fluid flow to pass over a maximized surface area. As noted inthe examples, wavyplate channel sides may, or may not, include acatalyst coating. FIG. 5C shows a channel section with catalyst coatingon combustor side 55C of the channel wall opposite vaporizer side 55V.Channel length determines the residence time of a fluid increment whichin turn depends on pressure change in the channel. In a representativechannel unit, with a nominal channel gap of 250 microns +/− 50 microns,the channel width to depth aspect ratio, as shown as W:D in FIG. 5D andFIG. 5E may be in the range from 1:10 to 1:100 such that surface area inthe channel is maximized as a design parameter.

[0038] The combustor sections include a catalyst for inducingcombustion, as noted with the embodiments of FIGS. 2B and 3B. A catalystcombustor may precede the module, eliminating the need for combustion tooccur in the heater section of the HEX hydrocarbon vaporizer. In suchembodiments, the module is a micro component heat exchanger, withoutcatalyst on either side of the wavyplate separator.

[0039]FIG. 6A, FIG. 6B and FIG. 6C illustrate sandwich assemblies ofheat exchanger vaporizer/combustor units. FIG. 6A shows stacked oradjacent units, 50 and 50′ of a HEX module such as shown in FIG. 5B.FIG. 6B and FIG. 6C are cross section and exploded views of acombustor/vaporizer/combustor assemblies in which two separatedwavyplates 65 and 66 define the operative sections 60cH (hydrogencombustor), 60v (hydrocarbon vaporizer) and 60cHC (hydrocarboncombustor), of a unit as described with reference to FIG. 4A. Anappropriate face plate manifold introduces the flow of fluid to thecentral vaporizer section of the unit. In the example of FIG. 6C, inletand outlet orifices for the respective combustor-heater/vaporizer andcombustor-heater sections are shown at 61I and 61O, 65I and 66O and 63Iand 63O. Inlet and outlet are not intended as terms restrictive of thedirection of fluid flow as flow may physically be co-flow or counterflow in either direction in the adjacent channel sections. Similarly,the orifices indicated may comprise alternately shaped openings and/ormanifolds that appropriately direct the fluid flow into the respectivechannels in the designated sections of a HEX module. As discussed above,catalyst may not need to be included in the heater side channels of aHEX module when hydrogen or hydrocarbon combustors precede therespective heater side as shown, for example, in FIGS. 2B, 3B, 4B and4C.

[0040] Gasoline-like fuel is a preferred hydrocarbon for use in thesystem, because of its widespread production and distribution network,its general availability and its utility as a feed stock in the hydrogenreforming process. The start module is scalable as a micro component tomeet varying requirements in which incremental design units aredetermined by the number of channels in the unit sections. Fluid flow isinduced through the channels as a result of pressure differentials inthe order of a differential pressure drop of less than 100 psi. Thelaminar flow through the channels provides a low pressure drop in thesystem.

[0041] Water, in the form of condensate from fuel cell system exhaust,is introduced through a pump as is the hydrocarbon component introducedunder pressure. Reaction balance in the system is achieved by variablyadjusting pump and compressor pressures to maintain fluid flow such thatreactions are balanced.

[0042] Having described the invention in detail, those skilled in theart will appreciate that, given the present disclosure; modificationsmay be made to the invention without departing from the spirit of theinventive concept herein described. Rather, it is intended that thescope of the invention be determined by the appended claims.

1. A module for initiating the on demand start up of a of hydrogen gas producing cycle for powering a fuel cell system comprising: co-operatively engageable micro component heat exchangers having micro channels therein which direct laminar flow of fluid on opposite sides of a separator therein, the heat exchangers being operatively interconnected with switchable sources of hydrogen and liquid hydrocarbons in a relationship in which: in a start mode, a first side of a first heat exchanger is interconnected with the source of hydrogen and the second side of the first heat exchanger is interconnected with the source of liquid hydrocarbons, whereby, upon opening of the switches, hydrogen and hydrocarbons are introduced to the respective first and second sides of the heat exchanger, the first side providing instantaneous heat energy to the second side to vaporize the hydrocarbons that are introduced therein, and the second side is interconnected with the second heat exchanger in a relationship such that vaporized hydrocarbons are introduced to a first side of the second heat exchanger to provide heat energy to the second side thereof to vaporize hydrocarbons that are introduced to the second side thereof; the second side of the second heat exchanger being interconnected with the gas producing cycle in a relationship such that vaporized hydrocarbons exiting from the second side are introduced into the hydrogen producing cycle as an energy source for combustors therein and as a feedstock component for the production of hydrogen, whereupon, upon initiation of the gas producing cycle, the first side of the second heat exchanger is connected to off gas from the fuel cell system and the flow of hydrogen to the first side and the flow of hydrocarbons to the second side of the first heat exchanger is switched off.
 2. The start module of claim 1 in which one side of at least one heat exchanger comprises a combustor for the generation of heat energy and includes a catalyst.
 3. The start module of claim 2 in which the combustor comprises a micro channel for directing laminar fluid flow in which a side segment of the channel is coated with a catalyst.
 4. The start module of claim 2 in which the combustor comprises a metal foam catalyst module interconnected with the heat exchanger.
 5. The start module of claim 2 in which the combustor comprises a flame combustor.
 6. The start module of claim 2 or claim 3 or claim 4 in which the catalyst is selected from one or more than one of platinum and palladium.
 7. The start module of claim 4 in which hydrogen is combusted in the catalyst module and heat energy from the combustion is introduced to the first side of the first heat exchanger.
 8. The start module of claim 1 in which the hydrogen gas producing reactor is a steam reformer.
 9. The start module of claim 1 in which the hydrogen gas producing reactor is an auto thermal reformer.
 10. The start module of claim 1 in which co-operatively engageable heat exchangers include two separately enclosed units, each having a central volume separated by a wavyplate, in which the volume on one side of the wavyplate comprises heater channels and the opposite side of the wavyplate comprises vaporizer channels.
 11. The start module of claim 1 in which co-operatively engageable heat exchangers include a pair of spaced apart wavyplate separators disposed in the volume of the same enclosure, the separators defining a central vaporizer section disposed between facing sides of the wavyplates and separate first and second combustor/heater sections on the oppositely facing sides of the wavyplates.
 12. The start module of claim 1 in which a minor portion of the vaporized hydrocarbons exiting from the second side of the second heat exchanger are introduced into the first side of the second heat exchanger and provide an energy source for the vaporizer on the opposite side thereof.
 13. The start module of claim 12 in which the minor portion of the vaporized hydrocarbons is in the order of approximately 3% to approximately 3% by mass.
 14. The start module of claim 12 in which the minor portion of the vaporized hydrocarbons exiting from the second side of the second heat exchanger introduced into the first side of the second heat exchanger are mixed with fuel cell off gas.
 15. The start module of claim 1 in which micro channels formed in the separator have a width to depth aspect ratio of less than 1:100.
 16. The start module of claim 1 in which micro channels formed in the separator have a width to depth aspect ratio greater than 1:10.
 17. A module for initiating the on demand start up of a of hydrogen gas producing cycle for powering a fuel cell system comprising: a micro component heat exchanger having micro channels therein which direct laminar flow of fluid on opposite sides of a separator therein operatively interconnected with switchable sources of hydrogen and liquid hydrocarbons and to the fuel cell system in a relationship in which: in a start mode, a first side of the heat exchanger is interconnected with the source of hydrogen and the second side of the heat exchanger is interconnected with the source of liquid hydrocarbons, whereby, upon opening of the switches, hydrogen and hydrocarbons are introduced to the respective first and second sides of the heat exchanger, the first side providing instantaneous heat energy to the second side to vaporize the hydrocarbons that are introduced therein, the second side further interconnected with the first side in a relationship such that a minor portion of the vaporized hydrocarbons are introduced to the first side of the heat exchanger to provide heat energy to the opposite side thereof and the major portion of the vaporized hydrocarbons exiting from the second side are introduced into the hydrogen producing system as an energy source for combustors therein and as a feedstock component for the production of hydrogen, whereupon, upon initiation of the gas producing cycle, the first side of the heat exchanger is connected to off gas from the fuel cell system and the flow of hydrogen to the first side is switched off.
 18. The start module of claim 17 in which the minor portion of the vaporized hydrocarbons is in the order of approximately 3% to approximately 3% by mass.
 19. The start module of claim 17 in which the first side of the heat exchanger includes a catalyst.
 20. The start module of claim 17 in which a catalytic combustor is interposed between the source of hydrogen or the source of hydrocarbons.
 21. The start module of claim 18 in which a catalytic combustor is interposed between the source of hydrogen and the source of hydrocarbons.
 22. The start module of claim 17 in which a flame combustor is interposed between one or more than one of the source of hydrogen and the source of hydrocarbons.
 23. The start module of claim 17 in which the catalyst is selected from one or more than one of platinum and palladium.
 24. The start module of claim 18 in which the catalytic combustor comprises a module including a metal foam.
 25. The start module of claim 24 in which the metal foam includes one or more than one of platinum and palladium. 